When ones' scrotum extends longer than their testicles. Thus causing an excess of skin to hang from their penis. This is a very common incidence for men past 25 years in age. The skin itself also may slap against ones' leg in the event on a high speed situation, and some loose clothing.

"Dude did you see that guy in the changeroom?" - Guy 1
"Yeah man, he had a huge elephant ear. You could totally see his overhang" - Guy 2

A common phrase in baseball, elephant ears are simply when the pockets of a player's pants are seen outside of their slits (which happens often to back pockets which are in no way attached to the inside of the pants). Phrase made most popular by Duane Kuiper and Mike Krukow, San Francisco Giants TV broadcasters.